Apparatus for obtaining power from compressed air



Sept. 12, 1933.

APPARATUS FOR OBTAINING POWER FROM COMPRESSED AIR Original Filed July18, 1923 A TTORNE Y.

E. J. STODDARD 1926 4635 the apparatus embodying my invention.

remiss Sept.12,1933 i APPARATUS roa OBTAINING POWER FROM coMraEssEn Am 7Elliott r. Stoddard, HighlandPark, Mich. Application July 18, 1923,Serial No; 652,225

Renewed April 15, 1932 3 cas s. (01. p 60 59) My invention relates to anapparatus for obtaining power from compressed air. In the accompanyingdrawing:-

Figure 1 is a diagrammatic representationof Figure 2 is a modified formotFigure I. Figure 3 is a detail showing the relative position of thecranks of the apparatus of Fig. 2;

Figure 4 is a detailed perspective view of the crankshaft of Figure 1,showing the relative positions of the cranks. 1 I a is the workingcylinder having the piston ap and b is an auxiliary cylinder having thepiston of the apparatus F op adapted to reciprocate therein.

The cylinder 1) is made up of two parts, the upper 193 being united by aconventional flange to t the lower, 272, with a heat insulating washerbe between said flanges.

The pistons up and bpmay be connected to c is a. coolingreservoirpreferably of such in-.

ternal capacity that the operation of the engine shall not'vary thepressure therein to a substantial extent, and the passages between thecylinders should be of as small internal volume as practicable so as notto introduce objectionable clearshoe. The reservoir c is shown as madeup of tubes, the ends of which are connected to headers and water maybeused in the usual way around the tubes for cooling the same; p

d is an inlet and e a discharge valve at the upper end of the cylinder1), and f is an inlet and g a discharge or exhaust valve at the upperend of the cylinder d. i

be is a pipe or conduit leading from ,thecooler c to the cylinder bthrough the port of the valve :1. cab is a pipe or conduit" connectingthe cylinders a and b to the intake port f of the cylinder a. ac is apipe or conduit connecting the cylinder a with the reservoir 0 throughthe port of the exhaust valve g. 9' is an open pipe connecting thereservoir c with the lower end of the cylinder a.

h is a heater. This is represented conventionally as two headers joinedby pipes. 712 is apipe leading from the pipe cab to the upper end of theheater h and k3 is a pipe leading from the lower end of the heater h. tothe lower end of the cylinder b.

The valves (1, e, f, g, are preferablymechanically controlled but asvalve-controlling mechanism is conventional and well understood the de"tails are not shown and conventional automatic valves may be used.

The operation or the form of the device shown in Fig. lis as follows:-

,The reservoir 0 and connecting passages are filled with compressed airat a high pressure,

; it is heated to a high temperature and then passed. through the pipeh3 to the lower end of the cylinder 1). It will beobserved thatgthepressure on both sides of the piston 'bp during this operation isthe-same but that the air is stroke, the cranks being parallel as shownat K211 andv K311, Figure 4. .The valve e is now closed and the valveopened and the. piston up descends on its working stroke; the airpassing from below'the piston bp, again through the heater h and actingupon the greater area of the piston up to produce the working stroke.When the piston aphas reached the lower end of its stroke the valve 1 isclosed and the valve. 9 opened, andas said piston rises it dischargesthe air above it through the pipeac into the cooler c where theremaining heat is removed. In the apparatus of Fig.2 the parts aremainly the same as in "Fig; land are lettered the same, the diiTerencebeing'that the port of the valve e is connected directly to the port ofthe valve f with the heaterh interposed in the conduit .ab'andthepistons up andbp' are in different phases. I have shown thepiston by? as90 degrees behind the pistonap. In Fig. 2. the lower,-

end of the cylinder 19 is connected with the res 1 ervoir c by an openpipe 7'2. V p v V I0 indicates the crankshaft; k2 the crank connected tothe piston up, and k3 the crank connected to the piston lap. Theoperation of the form of the deviceshowninFig. 2 is as follows:--

The compressed air is taken in past thevalve d on the descendingstrokeof the piston bp. The piston bp then rises and compresses the airabove it to a still higher pressure, in this instance; to about half ofits stroke. The piston up is then at the top of the stroke and beginningto descend. The valves e and f are now open and the air compressed abovethe piston bp is passed through the conduit ab and heater h, wherein itis raised to a higher temperature and into. the cylinder at above thepiston ap, acting upon the greater area ,of surface of said piston. Whenthe piston bp has reached the top of its stroke the valves e and areclosed and the compressed air above the piston up is allowed has causedno additionalwork as the expansion cylinder is also the balancingcylinder.

What I c1aim'is:1- I v 1. The combination of a reservoir 0 having coldairunder pressure therein, a cylinder 2; closed atboth ends having areciprocating piston therein and having its intake port at one end con--nected to said reservoir and its exhaust port at said end' connected tothe intake port of the other end, a working' cylinder a, with areciprocating piston; therein the exhaust from the lastnarned end of thecylinder communicat-.

ing with the intake of the cylinder (2 so as to transfer said portion ofair to said working cylinder ateach stroke, means for heating the air inthe connection between the endsof the first mentioned cylinder, theexhaust of the cylinder a leading to the reservoir 0, said pistons beingoperatively connected.

2. The combination of a reservoir or cold compressed air at a highpressure, a cylinder with a piston adapted to reciprocate therein, asecond cylinder with piston adaptedto reciprocate therein, the intake ofthe first cylinder communicating with said reservoir and its outletcommunicating with the intake of thesecond cylinder,

said pistons being connected and so arranged that the pressures thereonshall balance each other, said cylinders being of sucha capacity thatthe air passing between them shall be held at approximately constantvolume, a heater for the air passing from one of said cylinders to theother, and a working cylinder adapted to receive theheated air from thesecond cylinder, expand the same and return it to said reservoir.

3; The combination of a reservoir of cold compressed'air' at a highpressure, a cylinder with a piston adapted to reciprocate'therein, asecond cylinder with a piston adapted to reciprocate therein, the intakeof the first. cylinder communicating with said reservoir and its outletcommunicating with the intake of the second cylinder, said cylindersbeing of'such a capacity that the air passing between them shall be heldat approximately'con'stant volume, a heater for the air passing from oneof said cylinders to the other, and a working cylinder adapted toreceive the heated air from the second cylinder, expand the sameandreturn it to said reservoir.

. ELLIOTT J. STODDARD.

